1. Technical Field
This invention relates to lighting systems. Specifically, the invention refers to modular lighting systems with separately replaceable lighting elements.
2. Related Art
Fluorescent lighting has been widely used for decades. A fluorescent luminaire is typically organized as a separate fixture into which one or more lamps are mounted. A fixture base provides for mechanical mounting and often provides light reflectors to direct light in desired directions. These fixtures are commonly mounted on, mounted within, or suspended from ceilings. Ballast circuits needed for fluorescent light operation are typically part of the fixture base and permanently mounted to an inaccessible area of the fixture base. Fluorescent lamps are generally cylindrical and are commonly referred to as tubes or bulbs.
Common luminaires provide wiring to power the lamps and ballast circuit. Although circuit details vary, depending primarily on the ballast circuit, an electrical mains supply, typically 110 or 220 volts, is routed to the ballast and lamp. Fixtures with multiple lamps are typically configured to use one ballast circuit for all of the bulbs.
Prior fluorescent lighting systems, particularly those with a single ballast and multiple bulbs, have some limiting traits:                Component failures are not isolated.                    Failure of one bulb will often prevent proper operation of other bulbs in the fixture because the bulbs electrically interact through the shared ballast.            Failure of the single ballast circuit will prevent operation of any of the bulbs in the fixture.            Failure of the ballast circuit is often repaired by replacement of the entire fixture.                        The bulbs must be operated in an all or none manner.        The ballast and bulbs may operate inefficiently. It may be necessary to change ballast circuits to fully utilize improved bulbs, and vice versa.        